With the heretofore known trucks, the vehicle control cab is exactly tailored to the respective motor-steering unit, practically forming an integral unit therewith. If a different vehicle control cab, for example for military purposes or a large capacity cab having a resting or sleeping cabin, is desired, then each specific case requires considerable structural modifications, at least of the entire front of the vehicle, all at substantial cost.
If, as mentioned above, additional resting or sleeping cabins are required, especially on large capacity vehicles and tractor semi-trailer combinations, the additional cabins have up to now been arranged in the vehicle control cab behind the driver's seat directly above the seat backs. This increases the length of the control cab by at least 70 to 80 cm, which in turn causes a loss of the useful length of the vehicle.
The height of the vehicle, on the other hand, is determined by the payload carrier or the semi-trailer, and often amounts to as much as four meters. In comparison, the heretofore known large capacity cabs have a height which is about 1 meter less than the height of the payload carrier or semi-trailer. In other words, the height of the vehicle is poorly utilized. Moreover, unfavorable aerodynamic conditions occur.